As previously reported, Longbow analyst Alton Stump downgraded Yum! Brands (YUM) to Underperform from Neutral, noting that the stock is trading at nearly a 25% premium to its closest quick-service peers despite similar comp growth, unit growth, and leverage.

Confidence among his Taco Bell franchisee contacts in new product development has "waned significantly" since former Taco Bell head Brian Niccol left to become CEO of Chipotle (CMG), said Stump, who thinks it is highly likely Taco Bell's comp growth profile will slow meaningfully in coming quarters.

He also expects Pizza Hut's comps to "remain stagnant to up 1% at best over the next 18+ months," said the analyst, who has a $91 price target on Yum! shares.